使用盒狀耦合結構濾波器製作微帶線頻率雙工器

Abstract

本論文描述一種微帶線盒狀耦合濾波器來製作頻率雙工器。盒狀耦合結構濾波器可以以近似的物理佈局產生一個在上止帶或下止帶之傳輸零點，用它來設計頻率雙工器將非常的簡潔且有很佳的性能。此論文提出了一種以T型雙模諧振器的方式來實現此種濾波器，它具有對稱的佈局、無下止帶的偽頻通帶、與面積小之優點。實做的雙工器與模擬的結果非常吻合。

This paper describes the microstrip box-section filter to realize a diplexer. Bandpass filter with box-section coupling scheme has the property of zero-shifting characteristic. Zero shifting means that a filter can have a lower stopband or a upper stopband transmission zero just by changing the resonator length and the physical layout are roughly identical. This zero-shifting characteristic is very helpful to design a good diplexer. Here, we propose a T-shaped two-mode resonator to implement the box-section filter. The filter has the benefits of symmetric layout, free from lower stopband spurious passband, and small size. The measured performance matches well with the simulated results.